Set "User-Agent" header
Set "User-Agent" header

Newer versions of the Cisco API require this to be one of "REST API
Agent", "ASDM" or "CSM".

Signed-off-by: Stephen Hoekstra <2371e4836dca2b4ff2f5fe1e3b942f4fa01b2f56@schubergphilis.com>

xanzy/go-ciscoasa